Finishing a wall is a necessary step in creating a surface that's not only structurally sound, but pleasing to the eye as well. One method to finishing a wall is to apply a layer of textured concrete. You can place the concrete covering onto any clean and stable surface, spreading a layer of material that you can then texture as desired. Once dried, the surface is strong and durable, needing little maintenance over the years to retain its look. In addition to providing a pleasant looking surface, a layer of textured concrete adds insulation to your wall, along with a layer of waterproofing.
Prepare the wall for the concrete. Clean the surface of the wall with a pH-neutral cleanser, scrubbing the wall with a scrub brush to remove any dirt from its surface. Clear any cracks present in the wall of debris using a wire brush to scrape the cracks. Fill cleared cracks with joint repair sealant, injecting the sealant into the cracks until it's even with the surrounding wall surface. Scrape the surface of the sealant with a putty knife to level it out and then wait 24 hours for the sealant to dry.
Mix a large enough batch of surface bonding cement to cover 20 square feet of wall surface in a large bucket following the manufacturer's directions. Use an electric drill equipped with a mixer attachment to obtain a smooth mix of the cement that's the consistency of paste.
Wet the surface of the wall slightly using a damp sponge. Spread the cement along the surface of the wall with a steel trowel. Layer the cement to a one-eighth inch depth, applying the cement to the wall working from the wall base upwards. Cover the 20-foot section of wall with the cement using even strokes applied leaving as few lines on the surface of the cement as possible.
Wet a clean steel trowel and smooth the surface of the applied cement. Gently move over the lines left by the cement application process, smoothing them until they are no longer noticeable.
Finish covering the wall with the cement, repeating the application process.
Texture the surface of the covering. Choose a texturing that creates the look you desire. Common texturing methods are to stipple the surface, using a stiff brush to go over the cement creating a random brushed texture. Another texturing process is to press the flat of the trowel randomly into the surface of the cement creating a series of shapes. Add coloured stones to the surface for a third option. You can use anything that leaves a visible impression in the surface of the wet cement to create the textured concrete surface for your wall.
Step back and examine the textured effect from where people will see the wall most often. You can change the texture by smoothing the surface with the trowel and trying again.
Cover the wall with curing blankets attached to the ceiling with a series of tacks. Make sure the blankets block the surface of the concrete without touching it for 48 hours so that the cement can begin to cure hard without the texture being disturbed.
Remove the curing blankets and allow the surface to complete the curing process for the time suggested by the bonding cement manufacturer.
Prevent cracks from developing in the textured surface by using a concrete groover to cut vertical lines into the surface as control joints to allow for expansion and contraction during temperature changes. Place the lines every 12 feet in the surface.